The general purpose brominated bisphenol A epoxy resin is a mature product for a long time, characterized in that after the long-term research and adjustment, the fiberglass laminate produced from the brominated bisphenol A epoxy resin shows good mechanical properties, electrical properties, dimension stability and other properties; it exhibits superior adhesion to glass, copper and other materials, so the stacked fiberglass laminates produced from bisphenol type brominated epoxy resins are widely used in electronic and aerospace industries.
The electrical properties of printed circuit board materials depend on the three major composites: (1) brominated epoxy resin, (2) filler (3) reinforcement material. As for the resin system, the substrate board with the specifications of FR-4 (Tg 140° C.) made from a current general purpose brominated bisphenol A type epoxy resin (such as Nan Ya Plastics Corporation's NPEB454A80) and glass fiber (E glass) shows about 4.6 Dk value which is unable to meet the requirements in the field of a high-speed high-frequency signal transmission, while new materials, such as BT (bismelaimide-triazene), cyanate ester, PTFE (poly tetra-fluoroethane), are introduced one after another into the application area, but various systems have its advantages and disadvantages, such as the fluorine resin PTFE shows low dielectric constant, low dissipation factor, low water absorption, but has shortcomings e.g. low Tg, high prices, poor processabilty, bad adhesion with copper foil; generally speaking, new materials used in the production process of fiberglass laminates and the production process of fiberglass laminates turned into printed circuit boards, the deviation between its processing conditions and conventional fiberglass laminates is too much to be widely used.